Survival estimates for juvenile fish subjected to a laboratory-generated shear environment

Juvenile rainbow trout Oncorhynchus mykiss and steelhead (anadromous rainbow trout), fall (age-0 and age-1) and spring Chinook salmon O. tshawytscha, and American shad Alosa sapidissima were exposed to shear environments in the laboratory to establish injury-mortality thresholds based on estimates of strain rate. Fish were exposed to a submerged jet having exit velocities of 0 to 21.3 m/s, providing estimated exposure strain rates up to 1,185/s. Turbulence intensity in the area of the jet where fish were subjected to shear was minimal, varying from 3% to 6% of the estimated exposure strain rate. Injuries and mortalities increased for all species of fish at strain rates greater than 495/s. American shad were the most susceptible to injury after being subjected headfirst to a shear environment, while steelhead and rainbow trout were the most resistant. There was no apparent size-related trend in susceptibility to high shear except that age-0 fall Chinook salmon were more resistant to shear environments than age-1 fall Chinook salmon. All groups of test fish exposed headfirst to high-shear environments had higher injury-mortality rates than fish introduced tailfirst at similar strain rates. These results document the relationship between fish injury and a fluid force present at hydroelectric facilities and provide biological specifications for improving fish passage and survival

Perioperative Fully Closed-Loop Insulin Delivery in Patients Undergoing Elective Surgery: An Open-Label, Randomized Controlled Trial

OBJECTIVE Perioperative management of glucose levels remains challenging. We aimed to assess whether fully closed-loop subcutaneous insulin delivery would improve glycemic control compared with standard insulin therapy in insulin-requiring patients undergoing elective surgery. RESEARCH DESIGN AND METHODS We performed a single-center, open-label, randomized controlled trial. Patients with diabetes (other than type 1) undergoing elective surgery were recruited from various surgical units and randomly assigned using a minimization schedule (stratified by HbA1c and daily insulin dose) to fully closed-loop insulin delivery with fast-acting insulin aspart (closed-loop group) or standard insulin therapy ac-cording to local clinical practice (control group). Study treatment was adminis-tered from hospital admission to discharge (for a maximum of 20 days). The primary end point was the proportion of time with sensor glucose in the target range (5.6–10.0 mmol/L). RESULTS Forty-five patients were enrolled and assigned to the closed-loop (n 5 23) or the control (n 5 22) group. One patient (closed-loop group) withdrew from the study before surgery and was not analyzed. Participants underwent abdominal (57%), vascular (23%), orthopedic (9%), neuro (9%), or thoracic (2%) surgery. The mean proportion of time that sensor glucose was in the target range was 76.7 ± 10.1% in the closed-loop and 54.7 ± 20.8% in the control group (mean difference 22.0 percentage points [95% CI 11.9; 32.0%]; P < 0.001). No episodes of severe hypoglycemia (<3.0 mmol/L) or hyperglycemia with ketonemia or any study-related adverse events occurred in either group. CONCLUSIONS In the context of mixed elective surgery, the use of fully closed-loop subcutaneous insulin delivery improves glucose control without a higher risk of hypoglycemia. © 2022 by the American Diabetes Association.